1. Field of the Invention
The present invention relates generally to a photographic developing system in which developing, fixing and washing are automatically conducted in series, and more particularly to a device for venting fumes such as gases, smoke and vapor, which are unavoidably given off during developing and fixing.
2. Description of the Prior Art
In known automatic developing systems, working solutions, such as developer and a fixing solution, are heated to as high a temperature as 30.degree. to 40.degree. C. The solutions are held in separate tanks. The heated solutions emit fumes. The fumes corrode mechanical components of the system.
In addition, the fumes tend to stick in droplets to the inner sides of the tanks' covering the drops grow and eventually fall into the tanks. When droplets of developer fall into a fixing tank, no serious problem arises. However, if the fixing solution (in droplet form) mixes with developer, the developer is fatally degenerated so that development becomes difficult. If droplets of developer fall onto a photosensitive material travelling along the crossover track, uneven treatment is likely to occur. Thus, removal of fumes is essential to development.
In line with the demand in the industry, a developing system has been proposed which includes a device for letting out fumes. The system is disclosed in Japanese Utility Model Publication (examined) No. 59-26356. This prior art system includes an exhaust pipe provided in an upper section thereof. The exhaust pipe is connected to a blower so as to vent fumes from the system.
There is another developing system known in the art, which, instead of an exhaust pipe, includes outlets provided in lids or side walls thereof to let out fumes.
There is a further proposal disclosed in Japanese Patent Publication (unexamined) No. 61-151652. To explain the background of the present invention, this prior art developing system will be described in detail with reference to FIG. 8:
A film is passed through a developing tank 2, a fixing tank 3, a cleansing tank 4 and a dryer 5 all of which are provided in operational order in the system 1. The system 1 is provided with a tray-shaped gas collector 6 in its ceiling. The collector 6 includes a short pipe 7 connected to a discharge duct 8. The short pipe 7 is closed by a cap 7' so as to prevent treating solution and cleansing water from entering the exhaust outlet 7. The fumes are discharged through the duct 8.
The common disadvantage of the known devices mentioned above is that the gas collecting opening(s) whether in the form of a pipe or a bore, is/are located at only one or two locations within the entire system. This causes the fumes which are far from the opening to be left unevacuated from an system. In large-scale developing systems a larger quantity of the fumes are likely to be left unevacuated because of such uneven distribution of suction.
To solve this problem a large blower is employed to increase the suction power. The provision of a large blower requires a large accommodation space, increases the cost, and causes a noise problem.
In the system of FIG. 8, the film is normally fed from a feed section 10 along a route (indicated by the dotted lines) but when necessary, the film is supplied into the system midways along the regular route. For example, when unsensitized film capable of being handled in bright rooms are supplied, there is no need to pass the film through the darkroom; If the feed section 10 is a dark room and the other sections are bright, the film need not be introduced through the dark room but can be supplied through the bright rooms into the developing tank 2. This advantageously speeds up the developing process. Likewise, a special slit may be produced in an upper section of the drying tank 5 to dry a film already cleansed at another place. However, these specially made slits allow the fumes confined in system to escape therefrom. As mentioned above, leaked fumes corrode the mechanical components of system and cause a pollution problem. When the system has a built-in process camera and a printer, the high-precision mechanical components of these instruments are spoiled by leaked fumes.